The organisation has called for the state's premier, Ted Baillieu, to immediately suspend the jumps racing season.
Wirth asked how many more horses' welfare would be compromised by the jumps racing industry to give the community the impression that jumps racing was viable.
"What is even more disgusting is that our government has injected $A2 million of taxpayer's money into funding this cruelty.
"Clearly, a jumps racing event cannot be run safely or humanely.
"However, our state leaders have chosen to invest in an activity that clearly compromises horse welfare rather than in hospital beds, better education resources, law enforcement or a hundred other areas where this money is desperately needed.
"Racing Victoria Limited can shout from the rooftops that improving horse safety is a primary concern of theirs, but year after year we continue to see horses die, and can only assume that the vast number of jumps horses that disappear each year without a trace have done so because of injury."
The RSPCA said it failed to see how Racing Victoria had achieved its goal in any way.
The charity said the only way Racing Victoria could improve horse welfare is to stand by its original decision to ban jumps racing after the 2010 season instead of "bowing to peer pressure by a handful of jumps racing enthusiasts".
"It is time for our premier to step in and take the reins by responding to community expectations and getting rid of jumps racing once and for all," Wirth said.
Racing Victoria did not have the gumption to stand up to a small portion of the racing community, "otherwise we wouldn't have had to witness this death".